This reaps the benefit of the earlier patch, which changed the type of
CCID 3 states to use enums, in that many conditions are now simplified
and the number of possible (unexpected) values is greatly reduced.

In a few instances, this also allowed to simplify pre-conditions; where
care has been taken to retain logical equivalence.

[DCCP]: Introduce a consistent BUG/WARN message scheme

This refines the existing set of DCCP messages so that
 * BUG(), BUG_ON(), WARN_ON() have meaningful DCCP-specific counterparts
 * DCCP_CRIT (for severe warnings) is not rate-limited
 * DCCP_WARN() is introduced as rate-limited wrapper

Using these allows a faster and cleaner transition to their original
counterparts once the code has matured into a full DCCP implementation.
Signed-off-by: NGerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: NArnaldo Carvalho de Melo <acme@mandriva.com>

This fixes CCID3 to give much closer performance to RFC4342.

CCID3 is meant to alter sending rate based on RTT and loss.

The performance was verified against:
http://wand.net.nz/~perry/max_download.php

For example I tested with netem and had the following parameters:
Delayed Acks 1, MSS 256 bytes, RTT 105 ms, packet loss 5%.

This gives a theoretical speed of 71.9 Kbits/s. I measured across three
runs with this patch set and got 70.1 Kbits/s. Without this patchset the
average was 232 Kbits/s which means Linux can't be used for CCID3 research
properly.

I also tested with netem turned off so box just acting as router with 1.2
msec RTT. The performance with this is the same with or without the patch
at around 30 Mbit/s.

Signed off by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This adds a new function dccp_rx_hist_find_entry.

Signed off by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Just updating copyright and contacts

Signed off by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This fixes a small typo in net/dccp/libs/packet_history.c

Signed off by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NJörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: NAdrian Bunk <bunk@stusta.de>

A bunch of asm/bug.h includes are both not needed (since it will get
pulled anyway) and bogus (since they are done too early).  Removed.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

 - added typedef unsigned int __nocast gfp_t;

 - replaced __nocast uses for gfp flags with gfp_t - it gives exactly
   the same warnings as far as sparse is concerned, doesn't change
   generated code (from gcc point of view we replaced unsigned int with
   typedef) and documents what's going on far better.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

To start the timestamps with 0.0ms, easing the integer maths in the CCIDs, this
probably will be reworked to use the to be introduced struct timeval_offset
infrastructure out of skb_get_timestamp, etc.
Signed-off-by: NArnaldo Carvalho de Melo <acme@mandriva.com>

Renaming it to dccp_rx_hist_detect_loss.
Signed-off-by: NArnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Renaming it to dccp_rx_hist_add_packet.
Signed-off-by: NArnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NArnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

I'll now take a look at the other proposed TFRC DCCP CCIDs to find
more code that is now in ccid3.c and move to this module, the loss
event rate, calc_X, etc most probably will be moved there.

The main goal of these changes is to pave the way for the
implementation of more TFRC based DCCP CCIDs and to shrink ccid3.c,
reducing its complexity and helping in getting it rock solid.
Signed-off-by: NArnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NArnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

And put this into net/dccp/ccids/lib/, where packet_history.[ch] will also be
moved and then we'll have a tfrc_lib.ko module that will be used by
dccp_ccid3.ko and other CCIDs that are variations of TFRC (RFC 3448).
Signed-off-by: NArnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>